Hydraulic torque converter



Sept. 9, 1941. J. M. SIMPSON HYDRAULIC TORQUE CONVERTER Filed Feb. 23, 1940 www.

Patented Sept. 9, 19.41

*UNITED srAri-jS-@PATE mnanucronoun coNvnnrEa John M. Simpson, Muncie, Ind.,` assigner to Borg- Warner Corporation, Chicago, lll., a corporation of Illinois f Application February 23, 1940, SerlalNo. 329,291

Achims.- (c

tate in the same' direction as the pump when the direction of the fluid is such as to cause it to impinge upon the backs of the stator vanes, i. e., when there is no longer any torque conversion taking place. Under the latter condition, the stator is merely dragged along by the fluid without in any way assisting in carrying the load. Such action reduces the eiiiciency oi the converter, and consequently is undesirable.

It has been proposed to connect the stator to one of the other elements of the converter when it is no longer serving as a reaction member in order to assist either in imparting energy to the iiuid (connected to the pump) or to assist the turbine in extracting energy from the fluid to carry the load. Such prior proposals have been for the most part complicated, requiring that a brake be released and a clutch engaged. or vice versa, which is usually an awkward maneuver, and also requiring that the change from brake to clutch be properly timed so as to take full advantage of the -torque conversion.

The object of this invention is to provide a simple means for connecting a stator to one of the other elements of a torque converter after the stator is n o longer serving as a reaction member, said mea'ns being automatically operated.

'I'he preferred embodiment of this invention is shown in the accompanying drawing which for'ms a part of this specication, and in which:

Fig. l is a partial side elevation in section showingv a hydrodynamic torque converter in which the novel connecting means is installed;

and

Fig. 2 is a front elevation in section of the converter.

The connecting means comprises a centrifugally controlled clutch located in the core ring of the converter vand cooperating with a one-way brake on the stator, the clutch being designed to take hold when the eillciency of the converter is at a maximum.

Referring now to the drawing, the drive shaft l. so-54) I9 o! a prime mover `(not shown) is connected to the vaned pump element vI I, of a torque converter, the turbine element Ilot which is drivingly connected to driven shaft I3. 'li'hev stator Il `is splined to a collar I5 which is rotatably mounted on a sleeve I6 iixed to housing I1.

4Between sleeve I1 and collarl5 is a one-way brake I8 of kthe roller type which permits collar I5, and consequently stator I4, to rotate in the lsame direction' as turbine I2, but prevents the collar from rotating in the opposite direction. Whe'n the load on driven shaft I3 is great and turbine I2 is rotating slowly, the fluid with which the converter is filled tends to rotate stator I4 backwards and the latter then serves as a reac tion member to convert torque. On the other hand, when the load is light, turbine I2 rotates at a higher speed and the fluid tends to rotate the stator Il in the same direction as pump I2. One-way brake I8 releases under the latter condition and the stator is i'ree to rotate.

Normally, stator I4 would merely impede the progress of the fluid and materially decrease the eiiiciency of the converter. In accordance with this invention, however, the stator is connected to the driven turbine I2 and made to assist in carrying the load. The connecting means comprises an automatic clutch I9 which is so designed as to couple stator Il to turbine I2 at approximately the instant when the eiliciency of the turbine is a maximum.

Clutch I9 is located within core ring 2li of the turbine, the ring being dened by flanges 2I, 22

and 29 on pump II, turbine I2, and stator I4, re-

spectively. The space within core ring 2li is usually wasted and this location of clutch I9 consequently adds nothing to the size of the converter. Furthermore, clutch I9 is 'protected by the surrounding elements of the converter and is less likely to be tampered with when the converter is serviced.

The principal elements of clutch I9 are a pair of weights 2| and 25 mounted on pivots 28 and 21 respectively, on flange 22, and a drum 28 on iiange 23 of stator Il. Although two weights are shown, it is understood that the number may be increased as desired or found to be expedient, it merely being required that the weights be arranged about the turbine in a balanced relation. Each weight is provided with an extension opposite the pivots in the form of a shoe 29 which is adapted to bear upon drum 28 and thereby drive said drum. Weights 24 and 25 are normally heid in a retracted position by springs 30 set in recesses 3l in the weights and compressed against :oF-FICE turbine in extracting energy from the fluid.

pins 32 extending axially Yfrom ilange 22 and cooperating with extensions 33 on the weights'.v

Flange 22 is reinforced at 34 to accommodatepivots 2B and 21.

Flange 23 of stator I4 is reinforced at 35 and 36 to provide cylindrical surfaces to which drum 28 may be secured.- Drum 2Q is preferably made from @a mat'ialgwhich is adaptedpro'vide the necessary "friction when it is submerged in oil. It is secured to stator I4 by welding or otherwise. I

In operation, pump II willbe rotated bydrive shaft I0, setting the nuid in motion. As the speed of the fluid increases, it will impinge upon turbie I2 and. start said turbine to'rotating. Stator Il will be held against backward rotation by oneway brake I8 and the torque of the drive shaft I will be multiplied in driven shaftA I3. As the load on the driven shaft I3 is decreased, its speed and the speed of turbine I2 will increase. When.

the speed at which clutch I9 is set to operate is reached, weights 24 and 25 will be thrown out- I wardly a suiilcient distance to cause shoes 29 to engage drum 28 and couple stator I4 to turbine I2. This speed is preferably ,the speed at which the eiliciency of the converter as such is a maximum. From this point on, the converter acts'as a fluid coupling with `the stator assisting the It will be observed that the release of the brake isl automatic and thatno control is required to be actuated and coordinated with the clutch in order to provide a smooth transition from torque conversion to simple iiuid coupling oper- `ation. i

It is understood that the foregoing description is merely illustrativeof a preferred embodiment of the invention, and that the scope of the in-` vention is not to be limited thereto. but is to be determined by the appended claims.

I claim:

1. In a torque converter of the hydrodynamic type a pump element, a turbine element and a stator element, said elements defining a chamber for the circulation of uid, and means for locking the stator to the turbine, said locking means comprising a friction surface on the stator and centrifugally controlled means on the turbine adapted to grip the friction surface above a predetermined speed of rotation of the turbine.

2. In a torque converter of the hydrodynamic A type having concentric lpump, turbine and-stator elements dening a chamber for the vcirculation of uid, means for locking the stator to the. turbine to increase the efliciency of the converter,

`said `locking-means comprising a drum rotatable with the stator and centrifugally controlled friction means on the turbine adapted to engage-the drum above a predetermined speed of rotation of the turbine. f

3. In a torque converter of the hydrodynamic typey having concentric pump, turbine and stator elements dening a chamber for the circulation of fluid, said elements being formed from cast .materiaL means for locking the stator'to the turbine` to increase the efllciency of the converter, said locking means comprising a drum welded to the stator and formed from different material e than the stator, andpivoted weights on the turbine having friction shoes thereon adapted to contact the drum above-a predetermined speed of rotation of the turbine.

4. In av torque converter of the hydrodynamic type having concentric pump, turbine and stator elements made of cast metal and deninga chamber for thecirculation of fluid, a hollow.core ring in the chamber, and means within-the core ring for locking the stator to the turbine above a predetermined speedvof rotation of the turbine to increase the efliciency of the converter, said means comprising a drum of diierent material within the core ring and welded to the stator, and pivoted weights mounted on the turbine in the core ring and having friction shoes thereon adapted to contact the drum above a predetermined speed of rotation of the' turbine.

, JOHN M. SIMPSON. 

